Update ply_io.cpp

Reading a binary PLY file with faces and "vertex_indices" property crashes, if only a PointCloud is provided. Since the polygons_ member is set to 0 and untouched otherwise.

Worked in PCL 1.6, doesn't work right now with 1.7.1.

The ply2pcd sample program provided with PCL crashes as well.
Fix some whitespace issues
Add: tutorial for progressive morphological filter
add missing lines of code in bspline_fitting tutorial
Merge pull request #615 from Logrus/bspline-tutorial

add missing lines of code in bspline_fitting tutorial
Fix: make sure point is finite before vicinity search
Merge pull request #617 from nizar-sallem/fix_region_growing

Fix: make sure point is finite before vicinity search
Merge pull request #602 from chambbj/pmf-tutorial

Add: tutorial for progressive morphological filter
Matrix transform tutorial update
Merge pull request #621 from VictorLamoine/matrixTransform

Matrix transform tutorial update
Fix: alignment issue of SupervoxelClustering
Merge pull request #625 from chia0418/fix-supervoxel-clustering-alignment

Fix: alignment issue of SupervoxelClustering
Issue #564: Fix tutorials warning
Merge pull request #627 from VictorLamoine/issue564

Fix tutorials warnings (fixes #564)
fix progressive morphological filter to stop at the max window size
Merge pull request #630 from chambbj/fix-progressive-morphological-filter

fix progressive morphological filter to stop at the max window size
fix error in PFH tutorial
Improve ply2pcd help
Merge pull request #633 from xiangxw/fix_tutorial_pfh_estimation

fix error in PFH tutorial
Merge pull request #634 from VictorLamoine/improve_tools

Improve ply2pcd help